Enzyme-containing detergent composition

ABSTRACT

THE ENZYMES PRESENT IN AN ENZYME-BEARING DETERGENT COMPOSITION ARE STABILIZED BY SMALL AMOUNTS OF N-ACYL AMINO ACIDS WHOSE ACYL GROUPS ARE DERIVED FROM SATURATED OR UNSATURATED FATTY ACIDS HAVING 6 TO 20 CARBON ATOMS, AND THE ENZYMES ARE ALSO STABLE IN DETERGENTS IN WHICH THE N-ACYL AMINO ACIDS ARE THE PRIMARY SURFACTANT INGREDIENTS.

United States Patent Ofice 3,707,505 Patented Dec. 26, 1972 3,707,505 ENZYME-CONTAINING DETERGENT COMPOSITION Itsutoshi Maeda, Yasuichi Nomura, Kollei Hashimoto,

Akira Shimizu, Koji Mitsugi, and Ryonosuke Yoshida, Kanagawa-ken, Japan, assignors to Ajinomoto Co., Inc., Toyko, Japan No Drawing. Filed Dec. 28, 1970, Ser. No. 102,182 Claims priority, appllC53/lli0;l5-;3pall, Dec. 30, 1969,

Int. (:1. c11d 3/04 US. Cl. 252136 7 Claims ABSTRACT OF THE DISCLOSURE The enzymes present in an enzyme-bearing detergent composition are stabilized by small amounts of N-acyl amino acids whose acyl groups are derived from saturated or unsaturated fatty acids having 6 to 20 carbon atoms, and the enzymes are also stable in detergents in which the N-acyl amino acids are the primary surfactant ingredients.

' the anionic surfactants make the enzymes unstable. The

alkaline builders inactivate the enzymes at temperatures of 40 C. or more. The enzymes are even less stable in aqueous solutions having a pH of 10-11 as normally caused by the other ingredients of the conventional compositions.

A practically useful detergent composition in which the enzyme component is not significantly inactivated has not been available heretofore, and it is an object of this invention to provide an enzyme-bearing detergent composition wherein the enzyme is relatively stable.

It has now been found that the stability of the enzyme in detergent compositions of the type described is enhanced by the presence of an N-acyl amino acid, and its salts and esters, the N-acyl group being the radical of a fatty acid having 6-20 carbon atoms. The stabilizing agents of the invention are effective both in aqueous solutions and in dry detergent powders. The stabilizing agents of the invention will be referred to hereinafter as N-higher acyl amino acids for the sake of brevity.

To demonstrate the effectiveness of the stabilizing agents, two detergent bases were prepared. Base A consisted of 25% sodium n-dodecylbenzene sulfonate, 30% sodium tripolyphosphate, sodium metasilicate, 37% Glaubers salt, and 3% carboxymethylcellulose together with 0.1% protease (60,000 units/g. as determined by the modified Anson method described hereinbelow). Base B differed from Base A by substitution of sodium lauryl sulfate for the sodium n-dodecylbenzene sulfonate.

Aqueous 2% solutions of the bases having a pH of were mixed with the N-higher acyl amino acids listed in Table 1 in a concentration of 0.2%, each mixture was heated to 50 C. for 30 minutes, and the residual enzyme activity was measured. The term hydrogenated tallowyl is used in this specification for brevitys sake for the acyl radicals of the fatty acids in hydrogenated beef tallow. The term cocoyl will be used in an analogous manner.

In respective control tests, no N-higher acyl amino acid was added.

As is evident from Table 1, the stabilizing agents of the invention sharply reduce the loss of enzyme activity under the test conditions.

TABLE 1 Rate of residual activity, percent Deter- Detergent gent Expt base base N o. N -h1gher acyl ammo acid [A] [B] None 10 N-caproyl-lrvaline 28 N-capryl-L-valine.--.. 43 40 N-lauroylglycine 36 38 N-lauroyl-DL-alanine. 25 41 N-lauroylsarcosine- 64 39 N-lauroyl-L-leucine. 28 31 N-lauroyl-L-threonine 32 29 N-lauroyl-DL-methioniue. 31 35 N-lauroyl-e-aminocaproic aeid. 32 30 N-lauroyl-S-benzyl-L-cysteine 32 28 N-myristoyl-L-valine. 30 39 N-palmitoyl-L-valine. 55 31 N-palmitoylglycine. 30 39 N-palmitoyl-DL-alanine N-palmitoylsarcosine. 34 N-palmitoyl-L-leucine..- 35 32 N-palmitoyl-L-threonine 33 30 N-palmitoyl-L phenylalanine. 32 43 N-stearoyl-L-valine 31 35 N-undecylenoyl-L-valine 35 28 N-lauroyl-L-aspartie acid- 26 40 N-palmitoyl-L-aspartie aci 33 35 N-palmitoyl-L-asparagine 37 45 N -pahnitoyl-DL-homocysteie acid 29 30 N-hydrogenated tallowyl-glutamie acid- 32 31 N-lauroyl-L-arginine 36 85 N-palmitoyl-L-arginine 48 55 N-hydrogeuated tallowyl-L-arginine 38 58 N-lauroyl-L-arginine methyl ester- 36 N-lauroyl-L-ornithine methyl este 25 38 N,N-dimethyl-N-lauroyl-Irornithine.. 49 62 33 N-palmitoyl-L-lysine methyl ester 65 34 N-hydrogenated tallowyl-L-arginine-..-. 54 35 N -palmitoyl-L-lysine methyl ester 54 55 36 N-stearoyl-lrserine 37 43 Detergent bases A and B were modified to contain 0.4% protease, and batches of the modified bases were further mixed with the stabilizing agents of the invention listed in Table 2 in amounts of 0.8%. The powder compositions so obtained were stored at 84% relative humidity and 37 C. in a desiccator over saturated aqueous ammonium chloride solution for 7 and 14 days together with controls free from the N-higher acyl amino acids, and the residual enzyme activity was determined in percent of the initial value. The improved shelf life of the compositions according to this invention is evident from Table 2.

favorably affect the cleaning efficiency of detergent compositions containing enzymes.

Samples of cotton fabric artificially soiled (Empa 116) were soaked in a liquor ratio of 1:50 in aqueous 0.2% solutions of detergent base A without protease, with 0.001% protease (60,000 u./g.) but without N-higher acyl amino acid and with 0.001% protease and varying TABLE3 Expt.No 41 42 43 44 45 40 47 4a 49 P e s 0.01 0.001 0.0002 HGS, percent 0.1 0.02 0.005 0.001 CE,percent so 68 71 07 69 07 73 73 The amount of N-higher acyl amino acid which stabilizes the enzyme in a detergent composition may be 0.1 to 20% based on the weight of the detergent base or 20% to 1000% based on the enzyme. The effects of varying amounts of N-palmitoyl valine (P-V) and sodium n-hydrogenated tallowyl-L-glutamate (HGS) on the residual activity of 0.01% protease in an aqueous 2% solution of detergent base A after 10 minutes at 50 C. is evident from Table 4.

TABLE 4 Expt. No 50 61 52 53 54 55 G P-V, percent 0. 1 0.01 O. 002 HGS, percent--- 0.1 0.01 0. 002 Activity, percent 41 72 62 67 74 65 60 Detergent compositions of the invention may be powders, granules, pastes, or liquids. The stabilizers of the invention may be used to advantage in heavy-duty synthetic detergent compositions containing alkaline builder or in light-duty synthetic detergent compositions without alkaline builder whose predominant detergent agent is an anionic, cationic, or nonionic surfactant.

The N-higher acyl amino acids themselves have excellent surface activity and are stable in hard water. They may be used, therefore, as predominant active ingredients in detergent compositions which may further contain enzymes with or without builders. In such compositions, the enzymes are very stable.

When N-higher acyl amino acids constitute the primary surfactant in enzyme bearing compositions, other synthetic surfactants and builders may also be present. Good detergency and foaming ability are achieved even in hard water without the use of alkaline builders, such as sodium tripolyphosphate and sodium silicate, and the solutions prepared from such compositions may be neutral or only slightly alkaline so as to further enhance the stability of the enzyme.

The results of comparison tests between various detergent compositions respectively containing protease, amylase (10,000 u./g. from B. subtilis), and lipase (20,000 u./g.) as shown in Tables 5, 6, and 7 together with controls. Cleaning efiiciency was determined in the manner described with reference to Table 3 after minutes and minutes laundering. The residual enzyme activity was determined at ten times the concentrations indicated in the tables after 30 minutes heating to 50 C. (protease) or C. (amylase, lipase). Protease activity was determined by the modified Anson method in which casein is used as the substrate, and 1 unit is the amount of protease which liberates 1 g. equivalent of tyrosine per minute at 37 C. Amylase activity was determined by the modified Wohlgemuth method in which 1 amylase unit is the amount of enzyme which reduces the iodine color of 1 ml. of 0.65% soluble starch solution to an absorbance of 0.300 at 660 mp. in 10 minutes at 40 C. Lipase activity was determined by the method of Yamada et al. [J. Agric. Chem. Soc. Japan 36 (1962) 860], one unit being the amount of enzyme liberating 1p. equivalent of acid per nunute.

TAB LE 5 Cleaning effieiency Detergent composition aiter- Rate of residual Expt. Amt., 10 30 activity, No. Ingredient g./d1. min. min. percent Detergent base [A] 0. 2 57 8 g; 00 70 5 0. 002 60 71 11 0. 60 "{Protease 0. 002 i 68 76 1 Disodium N-hydrogenated 61 tallowyl DLglutamate. 0. 2 67 75 52 Protease O. 002 Sodium N-lauroyl-DL- 0. 2 62 glutamate. 51 68 48 Protease 0. 002 0. 2

41 65 30 0. 0022 0. 64 "iProtease 0. 002 69 42 N-palmitoyl-L-phenyl- 0. 2 65 alanine 63 79 46 Protease 0. 002 ge atergelitI llolass [A] t d 0. 1 o ium y rogena e 0. 1 66 tallowyl-L-glutamate. 67 82 73 Protease 0.002 Detergent base [A] wherein 0, 2

soilfium n-dodetlsyl bdeiliazene su ate was rep ace y 67 sodium N-hydrogenated 66 77 6o tallowyl-L-glutamate. Protease 0. 002 Sodium Ncocoyl-L-gluta 0. 1

mate. 68 Sodium lauryl sulfate 0. 1 68 81 74 Glaubers salt. 0. 1 0. 002 0. 2

TABLE 6 Cleaning efiieiency Detergent composition after Rate of residual Exp Amt., 10 30 activity, N o Ingredient g./dl. min. min. percent Sodium lauryl sulfate 0. 2 70 Amylase 0. 002 39 59 80 Sodium lauryl sulfate 0. 1 Disodium N-hydrogenated 0. 1 71 tallowyl-DL-glutamate. 38 60 100 Amylase 0.002 Sodium ndodecyl benzene 0. 2 72- sulionate. 39 57 Amylase 0.002 Sodium n-dodecyl benzene 0. 1

sultonate. 73 Disodium N-hydrogenated 0. 1 39 61 tallowyl-DL-glutamate. mylase 002 TABLE 7 Cleaning etficieney Detergent composition after- Rate of residual Expt Amt. 10 30 activity, No. Ingredient g./dl. min. min. percent Sodium lauryl sulfate 0. 2 74 "{Lipase 0. 002 i 41 59 50 Sodium lauryl sulfate 0. 1 75 Disodiurn N -hydr0genated 0. 1 42 61 90 tallowyl-DL-glutamate. Lipase O. 002 Sodium n-dodecyl 0. 2 76 benzene sulfonate. 39 58 46 Lipase 0. 002 Sodium n-dodecyl 0. 1

benzene sultonate. 77. Disodium Nhydrogenated 0. 1 35 63 96 tallowyl-DL-glutamate. 0 002 Lipase The acyl groups of the N-higher acyl amino acids in the detergent compositions of the invention are those of saturated or unsaturated fatty acids having 6 to 20 carbon atoms, such as caproic, lauric, tridecanoic, decanoic, myristic, pentadecanoic, palmitic, margaric, stearic, and oleic acid, also of the fatty acid mixtures obtained from fats and oils, such as coconut oil, tallow oil, hydrogenated tallow oil, olive oil, soybean oil, corn oil, and the like.

The N-higher acyl amino acids may be used also in the form of their salts with alkali metals (sodium, potassium) or ammonium, with water soluble amines, particularly alkanolamines (mono-, di-, or triethanolamine) and triethylamine, with basic amino acids if the acyl group is attached to an acidic amino acid, or in the form of their acid addition salts with mineral acids (hydrochloric or sulfuric), organic acids (acetic acid, lactic acid, acidic amino acids if the acyl group is attached to a basic amino acid).

The amino acid moiety of the N-higher acyl amino acid may be an acidic amino acid (such as glutamic acid, aspartic acid, homocysteic acid, cysteic acid, aminoadipic acid), a basic amino acid (such as lysine, arginine, ornithine, oxylysine, diaminobutyric acid, histidine, isolysine), or a neutral amino acid (such as glycine, alanine, valine, serine, proline, leucine, isoleucine, oxyproline, methionine, phenylalanine, threonine, tryptophane, cystein, cystine, tyrosine, norvaline, norleucine, aminobutyric acid, aminoisobutyric acid, diaminopimelic acid, diaminooxypimelic acid, pantonine, taurine, aminovaleric acid, and aminocaproic acid). It may be optically active or racemic.

The N-methyl-N-acyl and N-ethyl-N-acyl derivatives of these acids also may be used, such as N-acyl derivatives of N-methylleucine, N-methylglycine, N-methylalanine, dimethyl ornithine, and also N-acyl peptide derivatives.

When the N-higher acyl amino acids of the invention are used in the form of esters, the esters may be the lower alkyl esters (methyl, ethyl, propyl, butyl) or higher alkyl esters (such as octyl, lauryl esters).

Alkaline or neutral protease, amylase, and lipase may be used in the detergent compositions of the invention singly or in mixtures of two or more.

If a synthetic surfactant is used as the predominant detergent component, it may be an alkyl benzene sulfonate, the sulfate of a higher alcohol or of an alkyl ethoxy ether, an a-olefin sulfonate, another alkylaryl sulfonate, a polyoxyethylene alkylphenyl ether, and may be mixed with a builder, other auxiliary agents (optical bleach, perfume, dye, CMC to prevent redeposition), the N-higher acyl amino acid, and the enzyme.

If the N-higher acyl amino acid is the sole or predominant surfactant, it may be combined with a builder, auxiliary agents, and the enzyme. The detergent composition in either case may be in the form of a powder, a shaped solid body, a paste, granules, a cream, an emulsion, or a solution, as may be required.

The detergent compositions of the invention have a long shelf life because of the stabilizing efl'ect of the N-higher acyl amino acids on the enzymes, and only little of the enzyme activity is lost during use. Detergency is adequate, because the N-higher acyl amino acids are equal or superior in this respect to conventional detergents with which they are fully compatible.

When the N-higher acyl amino acids constitute the predominant active agent in a detergent composition, the composition has excellent stability and detergency in hard water without need for alkaline builders which impair enzyme activity. The solutions are neutral or weakly alkaline so that enzymes not suitable for alkaline solutions may be employed singly or in mixtures. The solutions may be employed for degreasing wool, as hair shampoos, and as detergents for kitchen use. The N-higher acyl amino acids tend to protect the skin and rarely cause irritation. They also have antibacterial or bacteriostatic efiects.

The detergent compositions of the present invention may therefore be formulated as laundry detergents, for general kitchen use, for use in automatic dish washers, as shampoos, bar soaps, cleaning creams, tooth pastes, and for industrial use.

The following examples illustrate the preparation of detergent compositions of the invention.

Example 1 litre of water was added to a mixture of 2.5 kg. of sodium-n-dodecylbenzene sulfonate, 2.5 kg. of disodium N-hydrogenated tallowyl-DL-glutamate, 6 kg. of sodium tripoly-phosphate, 1 kg. of sodium metasilicate, 7 kg. of Glaubers salt and 0.6 kg. of carboxymethylcellulose, and the solution was spray-dried to obtain 18 kg. of white granular detergent. Laundry detergent was prepared by uniformly mixing the above granular detergent with 360 g. of granular protease.

Example 2 Powder laundry detergent was prepared by adding 12 g. of protease to a mixture of 250 g. of sodium N-hydrogenated tallowyl-L-glutamate and 5 g. of N-lauroyl-L- ornithine lauryl ester acetate.

Example 3 Laundry detergent was prepared by mixing 300 g. of the commercial laundry detergent, Tide (trade name, produced by The Procter & Gamble Company) with 6 g. of granular protease and 10 g. of dipotassium N-lauroyl- DL-aspartate.

Example 4 To a mixture of 500 g. of sodium lauryl sulfate, 10 g. of sodium N-palmitoyl-L-valine, 1.4 kg. of Glaubers salt and 50 g. of carboxymethylcellulose, 2 g. of optical whitening agent was added and thereafter 24 g. of powder from protease to obtain neutral laundry detergent in powder.-

. Example 5 50 g. of protease was mixed with a mixture of 3 kg. of sodium N-cocoyl-L-glutamate and 7 kg. of Glaubers salt. The obtained mixture was dissolved in water to make 60 litres and spray-dried to produce neutral laundry detergent for W001 and synthetic fibers.

Example 6 Deodorant cleaning cream was obtained by adding 0.1 g. of protease and a very small amount of perfume to a mixture of 35 g. of mineral oil, 12 g. of spermaceti, 2 g. of beeswax, 5 g. of N-lauroyl-L-arginine methyl ester DL- a-pyrrolidone-carboxylate, 2 g. of glycerin and 40 g. of water.

Example 8 Detergent for automatic dish washers was obtained by mixing 100 g. of ammonium N-tallowyl-D-glutamate, 1 g. of protease, 3 g. of lipase and 5 g. of amylase.

Example 9 Detergent for kitchen use was obtained by dissolving 5 g. of potassium N-lauroyl-DL-alaninate and 0.5 g. of protease in 200 g. of a commercial detergent for kitchen and Fats Co., Ltd.).

Example 10 A liquid dish washing detergent was obtained by adding 0.1 g. of protease and 1 g. of amylase to a mixture of 15 g. of lauryl alcohol ether sulfate, 10 g. of alkylamide of coconut fatty acid, 5 g. of ethyl alcohol and 2 g. of N- myristoyl-L-arginine butyl ester lactate.

What we claim is:

1. A detergent composition consisting essentially of an anionic synthetic surfactant, at least one enzyme selected from the group consisting of protease, lipase, and amylase, and an N-acyl amino acid, the amount of said surfactant being sufficient to make said enzyme unstable in the absence of said 'N-acyl amino acid, and the amount of said N-acyl amino acid being suflicient to enhance the stability of said enzyme in the presence of said surfac tant, the acyl group in the N-acyl moiety of said N-acyl amino acid being the acid radical of a fatty acid having 6 to 20 carbon atoms, the nitrogen of said N-acyl moiety being bound to the carbon chain in the amino acid moiety of said N-acyl amino acid.

2. A composition as set forth in claim 1, wherein the remainder of said composition essentially consists of at least one builder selected from the group consisting of sodium tripolyphosphate, sodium metasilicate, and Glaubers salt.

3. A composition as set forth in claim 1, wherein said N-acyl amino acid is an N-acyl derivative of an amino acid selected from the group consisting of glutamic acid, aspartic acid, homocysteic acid, cysteic acid, aminoadipic acid, lysine, arginine, ornithine, oxylysine, diaminobutyric acid, histidine, isolysine, glycine, alanine, valine, serine,

proline, leucine, isoleucine, oxyproline, methionine, phenylalanine, threonine, tryptophane, cystein, cystine, tyrosine, norvaline, norleucine, aminobutyric acid, aminoisobutyric acid, diaminopimelic acid, diaminooxypimelic acid, pantonine, taurine, aminovaleric acid, aminocaproic acid, and sarcosine.

4. A composition as set forth in claim 1, wherein said 'N-acyl amino acid is an N-acyl derivative of an alphaamino, beta-amino, or omega-amino acid.

5. A composition as set forth in claim 1, wherein said N-acyl amino acid is in the form of a sodium, potassium, or ammonium salt thereof or in the form of an alkyl ester thereof, said alkyl having up to 12 carbon atoms.

6. A composition as set forth in claim 1, the amount of said N-acyl amino acid being between 20% and 1000% of the amount of said enzyme.

7. A composition as set forth in claim 2, said builder being alkaline.

References Cited UNITED STATES PATENTS 3,574,120 4/1971 Siebert 252527 3,519,379 7/1970 Blomeyer 252'DIG 12 2,962,448 11/1960 Dvorkovitz 252527 2,880,178 3/1959 Rufi et a1 252-527 X 3,051,627 8/1962 Bradford et al. 252-DIG -12 MAY ER WEINBLATI, Primary Examiner UJS. Cl. X.R.

63, '68; 252Dig. 12, 527, 546 

